The 7.2 is a popular bike because of its price point but the 7.3 is the best value in the line. It's a lot more than just a component upgrade, the frame is lighter and made from higher quality aluminum, it shares the same frame as the 7.4 and the 7.5 with internal cable routing. The fork is light weight aluminium instead of steel like the 7.0-7.2, and every component in the drivetrain is an upgrade. The list goes on.